Re: KeyDown for arrows - C# Discussion Boards

13-Aug-03 15:23

thanks

I'm not an expert yet, but I play one at work. Yeah and here too.

Sort Array

Mazdak13-Aug-03 9:26

13-Aug-03 9:26

There is an Array.Sort() function that sort one dimensional array. How can I sort two dimensional based one of dimensions?

Mazy

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Re: Sort Array

Ista13-Aug-03 13:27

13-Aug-03 13:27

yeah extend the class and write your own algorithm for it. Arrays in .NET suck, they should have grabbed some more java ideas

I'm not an expert yet, but I play one at work. Yeah and here too.

KeyDown for arrows

S O S13-Aug-03 6:23

S O S

13-Aug-03 6:23

How can I get the KeyDown event to fire for the arrow keys?

Nnamdi Onyeyiri13-Aug-03 7:17

Nnamdi Onyeyiri

13-Aug-03 7:17

you have to override the IsInputKey method, so that it returns true with the key arrows.

protected override bool IsInputKey(Keys key)
{
   if (key.KeyCode == Keys.Up) return true;
   else if (key.KeyCode == Keys.Down) return true;
   else if (key.KeyCode == Keys.Left) return true;
   else if (key.KeyCode == Keys.Right) return true;
   else return base.IsInputKey(key);
}

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S O S13-Aug-03 8:27

S O S

13-Aug-03 8:27

I tried that, but when I put a breakpoint there, I see the function never gets called... hmm?

Nnamdi Onyeyiri13-Aug-03 8:40

Nnamdi Onyeyiri

13-Aug-03 8:40

hmmm, it should do, it does when i create controls, are you creating a control from scratch? or adapting a current one?

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Ista13-Aug-03 13:19

13-Aug-03 13:19

To override the form or custom controls

<br />
protected override bool ProcessKeyPreview( ref System.Windows.Forms.Message mes )<br />
		{<br />
			Keys keyCode = (Keys)(int)mes.WParam & Keys.KeyCode; <br />
 <br />
			if((mes.Msg == WM_KEYDOWN || mes.Msg == WM_KEYUP) && keyCode == Keys.Down  ) <br />
			{<br />
				MessageBox.Show("Arrow handled");<br />
				return true;<br />
			}<br />
			else<br />
				return false;  <br />
<br />
		}<br />

for other controls like a textbox

<br />
Form1_Load()<br />
this.myControl.KeyDown += new KeyEventHandler(this.MyKeyDownEvent);<br />
<br />
<br />
...<br />
<br />
<br />
private void MyKeyDownEvent( object sender, KeyEventArgs e )<br />
{<br />
   if ( e.KeyCode == Keys.A )<br />
        MessageBox.SHow("Hey you typed an AS");<br />
}<br />

there you go dude the above works for override the message loop for custom controls and the below works for controls inside your container.

nick

I'm not an expert yet, but I play one at work. Yeah and here too.

Ista13-Aug-03 13:21

updating treeview from another thread

13-Aug-03 13:21

Downt forget the defines, I dont know where they exist in c# so i just make them consts

private const int WM_KEYDOWN 0x100;
private const int WM_KEYUP 0x101;

your C++ include files have all the values inside the libraries.

nick

I'm not an expert yet, but I play one at work. Yeah and here too.

datagrid

mdolby13-Aug-03 5:26

mdolby

13-Aug-03 5:26

Hello,

I have two tables, I wish to display the child table on the datagrid.. and a specific column from the parent table.. For example |column1|parentcolumn3|column2|

The child table is related to the parent table via parentID, but this is not the parent column I wish to display..it is parenteColumnXX

Can this be done on a dataGrid?? I do not want for the parent table to be displayed as a link neither I just want one specific parent column to be displayed in the same datagrid as the child table..

Hopefully I manage to explain the situation correctly..
And as always I really appreciate any help offered!!
Thank you!

Ista13-Aug-03 13:24

13-Aug-03 13:24

Ista13-Aug-03 13:25

13-Aug-03 13:25

why sure you could but you will need to create either a view to maintain this or extend the grids functionality for data binding. I would try the first, first.

You will need to create your own tablestyles collection

see this web page

Like, DUDE, it has all the answers man!

nick

I'm not an expert yet, but I play one at work. Yeah and here too.

Ista13-Aug-03 5:00

Re: updating treeview from another thread

13-Aug-03 5:00

The error:

The action being performed on this control is being called from the wrong thread. You must marshal to the correct thread using Control.Invoke or Control.BeginInvoke to perform this action.

Begin the delegate call:

<br />
		private void Form_QueryOperation_Load(object sender, System.EventArgs e)<br />
		{<br />
			//LoadTreeView();<br />
<br />
			SampleSyncronized sampSyncObj = new SampleSyncronized();<br />
			SampSyncSqrDelegate sampleDelegate = new SampSyncSqrDelegate(sampSyncObj.LoadTreeView);<br />
			IAsyncResult aResult = sampleDelegate.BeginInvoke(tvOperation, null, null);<br />
<br />
			aResult.AsyncWaitHandle.WaitOne();<br />
<br />
			sampleDelegate.EndInvoke(aResult);<br />
<br />
<br />
		}<br />

Updating class

<br />
	// Syncronized class<br />
	[Synchronization()]<br />
	public class SampleSyncronized : ContextBoundObject<br />
	{<br />
		public void LoadTreeView( System.Windows.Forms.TreeView crossTV )<br />
		{<br />
			LoadTreeViewNow(crossTV);<br />
		}<br />
<br />
		private void LoadTreeViewNow(System.Windows.Forms.TreeView tv)<br />
		{<br />
<br />
                    add tree node codew here<br />

how do I catch the current main thread to update the trre view

I'm not an expert yet, but I play one at work. Yeah and here too.

Furty13-Aug-03 13:41

Furty

13-Aug-03 13:41

In the LoadTreeView method, your code should call the LoadTreeViewNow method using a delegate and Invoke, in order to ensure the treeview is updated on it's creator's thread.

public delegate void LoadTreeViewHandler(System.Windows.Forms.TreeView tv);

// Syncronized class
[Synchronization()]
public class SampleSyncronized : ContextBoundObject
{
public void LoadTreeView( System.Windows.Forms.TreeView crossTV )
{
Invoke( new LoadTreeViewHandler(LoadTreeViewNow), new object[] { crossTV } );
}

private void LoadTreeViewNo (System.Windows.Forms.TreeView tv)
{
 // add tree node code here
}

Re: updating treeview from another thread

Ista14-Aug-03 4:14

Re: updating treeview from another thread

14-Aug-03 4:14

Hey Furty,

PLEASE HELP!!!!

Furty wrote:
Invoke( new LoadTreeViewHandler(LoadTreeViewNow), new object[] { crossTV } );

What namespace or object does the Invoke statement belong to, it doesn't recognize the command. Is this a reflection method?

nick

I'm not an expert yet, but I play one at work. Yeah and here too.

Ista14-Aug-03 6:50

14-Aug-03 6:50

please help sir

I'm not an expert yet, but I play one at work. Yeah and here too.

XPath question

Mazdak13-Aug-03 0:55

13-Aug-03 0:55

Is it possible to make query from XML file with sort/filter option with XPath? Like ORDER BY/%LIKE% in sql language.

Mazy

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Kannan Kalyanaraman13-Aug-03 1:07

Kannan Kalyanaraman

13-Aug-03 1:07

I think it might be possible, check out XPathExpression.AddSort method. I've never used it, so I can be wrong.

- Kannan

Mazdak13-Aug-03 1:13

13-Aug-03 1:13

Thanks Kannan, I'll check it. Smile | :)

Mazy

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Anonymous13-Aug-03 4:42

Anonymous

13-Aug-03 4:42

http://www.topxml.com/xsl/articles/xsl_ado/

look for Sorting

Will

Arjan Einbu13-Aug-03 5:05

Arjan Einbu

13-Aug-03 5:05

Have a look at this:

public XPathNodeIterator SelectSorted(XmlNode node, XmlNamespaceManager namespacemanager)
{
	XPathNavigator nav = node.CreateNavigator();
	XPathExpression xpathExpr = nav.Compile("xpath_expression");
	xpathExpr.SetContext(namespacemanager);
 
	xpathExpr.AddSort("sort_expression", XmlSortOrder.Ascending, XmlCaseOrder.None, String.Empty, XmlDataType.Text);
 
	return nav.Select(xpathExpr);
}

Mazdak13-Aug-03 5:43

13-Aug-03 5:43

Thanks for your reply. How does xpath_expression or sort one look like? Like SQL?

Mazy

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